Deep in the bowels of the imposing North Block here, scores of men have been busy making 'halwa' -- sweet or bitter will only be known when finance minister P Chidambaram unveils the Union Budget tomorrow.

The story is that the top Finance Ministry officials every year participate in a ceremony of making a metaphorical 'halwa' just before being quarantined to give final shapes to the Budget.

While there is no official word on this 'halwa', which has a veil of secrecy to it, just like the main budget, it is said that the sweet dish is considered as a 'shagun' or good omen for the humongous tasks associated with this annual event.

The Budget press, which prints hundreds of reams of pages, is located in the basement of the high-security North Block, which gets further fortified during the Budget preparation. The printing is supervised by technical staff drawn from government presses.

So is the secrecy that government officials involved in the process of making Budget are not allowed to take their cellphones inside, leave alone meeting visitors. The Finance Ministry becomes out of bounds not only for journalists, who otherwise enjoy an easy access, but also for the usual visitors to the Ministry.

A complete quarantine of select officials and technicians is put in place about 10 days before the Budget presentation in Parliament. The printing is normally completed by February 24-25 and the documents are transferred to Parliament premises in the dead of the night on the eve of the Budget Day.

After being presented in Parliament tomorrow, the Budget would be discussed by lawmakers over coming months.

The Budget is likely to be passed by May, ending an over eight-month process that began on September 14, 2012.

It is on this date that the Finance Ministry issued its annual Budget Circular for the upcoming Union Budget. The circular informed all the ministries and departments about the start of Budget process and sought their inputs for the same.

This was followed by the Budget Division of Finance Ministry coordinating with various ministries and departments with regard to their revenue receipt budgets during October and November months.

The details of expenditure budget and estimates of borrowings and revenue were discussed during December and initial days of January.

The Finance Minister also began his consultations with sectoral representatives in January and met economists, trade unions, industry leaders and regulators among others.

In the meantime, ministries sent their plan estimates.The budget division, which is part of the Department of Economic Affairs in the Finance Ministry, compiles the broad framework for the bulky Budget documents.